What is 9 9 2 − 9 8 2 ?
Note: Try it without using a calculator.
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Best answer.
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You mean it's the best solution. All correct answers are the best.
difference of two squares. i really forgot it. i just guess for my answer and it is correct!
4th standard algebra fomula a^2 - b^2 =(a-b) (a+b)
very accurate answer
i really forgot the method to solve it nw i got it
good answer
I,ve got it
nice solution,but i prefer use (100-1)^2-(100-2)^2 to solve it cause to me ,it is much easier to do this by mental calculation
99^1-98^1 woulkd give us 1 so y cant the same logic be apllied here i mean both have increased by same proprtion so the difference should remain same
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because that only works with addition and subtraction, but this involves multiplication.
9 9 2 − 9 8 2 = ( 9 8 + 1 ) ( 9 8 + 1 ) − 9 8 2 = 9 8 2 + 9 8 + 9 8 + 1 − 9 8 2 = 2 ∗ 9 8 + 1 = 1 9 7
This is needlessly complicated. Just use the standard factorization of the difference of two squares.
The Same with Me! Greets bro! :)
i like your solution
Imagine a 98x98 square fitting inside of a 99x99 square. The remaining open space is the difference, which yields a row of 99, a column of 99, and an overlap. Thus 99+99-1=197
Thank you for this visual solution!
It's been a while since college algebra, so: mentally, 100^2=10,000. 99^2 is one 100 and one 99 less than that: 9,801. 98^2 is two 100's and two 98's less than 10,000: 9,604. The difference would be 200 if it weren't for the fact that 4 is 3 more than 1; therefore, the difference is 3 less than 200.
99^2 - 98^2 = (98+1)^2 - 98^2 = (a+1)^2 - a^2 = a^2 - a^2 + 2a + 1= 2*98 + 1 = 196 +1 = 197
a^2 - (a-1)^2 = (a + (a-1))(a - (a-1)) = (2a -1)(1) = 2a -1 here: a = 99; So: 2(99) - 1 = 197
9 9 2 − 9 8 2 = ( 9 9 + 9 8 ) ( 9 9 − 9 8 ) = ( 1 9 7 ) ( 1 ) = 1 9 7
Hence: a^2 - (a-1)^2 = a + a -1
A pattern of squares is that
a^2=b^2+(a+b)
Where a is the next number and b is the previous
99²-98²=
(98+1)(98+1)-98²=
98²+2(98)+1²-98²=
2(98)+1= 197
Difference of two squares formula: 99^2 - 98^2= (99 + 98)(99 - 98)= (197)(1)= 197
I did it by noticing the pattern of the difference in powers. I noticed that if I did
3 2 − 2 2 = 5
4 2 − 3 2 = 7
5 2 − 4 2 = 9
And so on. So I realized that the given the format a 2 − b 2 the answer was always ( b × 2 ) + 1
From there it was as easy as ( 9 8 × 2 ) + 1 = 1 9 7
99~2-98~2 =(99+98) (99-98)=197X1= 197Write a solution.
9 9 2 − 9 8 2 = ( 9 8 + 1 ) 2 − 9 8 2
= 9 8 2 + 2 × 9 8 + 1 2 − 9 8 2
= 1 9 6 + 1 = 1 9 7
99^2 - 98^2=(99+98) (99-98) = 197 (1) = 197
I forgot about difference of two squares, so I did this:
99^2 = (98+1)(98+1) = 98^2 + 98 + 98 + 1
so
99^2 - 98^2 = 98^2 + 98 + 98 + 1 - 98^2 = 98 + 98 + 1 = 197
Best way to work this out is visually, Imagine a 99 X 99 pixel grid then a 98 X 98 pixel grid on top of it, there will two 1-pixel lines forming an L-shape which give the answer, The lines are each 99*1 but with one common pixel. ie. ((99 X 1) X 2)-1
As a matter of pattern, if (2^2)-(1^2) = 3 and 1+2=the same, and (5^2)-(4^2)= 9and 5+4 =the same, and (7^2)-(6^2)=49-36=13=7+6, and so one, a pattern can be seen that a number squared minus one less than itself squared is equivalent to both numbers added, therefore, simply though pattern recognition, without actually having to actually "do" the equation itself, we can recognize that (99^2)-(98^2) is equivalent to 99+98, in other words 197. So yes, a calculator would have taken the fun out of that.
Difference between the squares of two consecutive numbers will be the sum of the two numbers always.
(a+1)^2 -a^2 = 2a+1
99^2 - 98^2 =99 99 -98^2 =(98+1)(98+1) -98^2 =98^2+2 98 +1 -98^2 =2*98 +1 =197
99^2 = (99 * 99)-(98^2) 99 * 99 = (98 + 1) (98 +1) - 98 98 = [(98 * 98) + (98 * 1) + (98 * 1) + (1 * 1)] - (98 98) =98+98+1 =197
(a+b)^2 = (a+b)(a-b), so it becomes 98+ 99 = 197
X^2-(X-1)^2 = X+(X-1) 99^2-98^2 =99+98=197
We use concept: a^2-b^2 = (a+b) (a-b) So, Obviously that 99^2 - 98^2 = (99+98)(99-98) = 197.
Difference of two squares results in 197.
(Sequential exponential pattern)
n=1 n^2=1 (n+1)^2 = n^1 +n x 2 +1 4 = 1 + 2 + 1 4=4
sub in 98 n^2-n^2+ n x 2 + 1 = the difference of the two squares which is 197
First, you should know the pattern of difference of two square numbers:
a^2 - b^2 = (a+b) (a-b)
Just follow the pattern/formula and you will get the answer.
99^2-98^2=(98+1)(98+1)^2-98^2 =98^2+98+98+1-98^2=98+98+1=196+1=197
Why dont we just use easiest solution? 99^2 - 98^2 = 99 + 98 = 197
square of a number s d sum of preceding square nd its double +1 ....... i.e.......2^2 = 4 .......3^2= 4+(2 2)+1..... (3^2)-(2^2) = (2 2)+1... ......in d same way ....(99^2) - (98^2) = (98*2)+1...
If n^2 is known, (n+1)^2 = n^2 + 2n + 1
The nth term for the differences between squares is 2n+1 . The question asks for the difference between the 98th and 99th squares, so we substitute 98 as n to find the 98th difference.
(2)98+1 = 197
Let a=98. Then 99^2 - 98^2 = (a+1)^2 - a^2 = a^2 + 2a + 1 - a^2 = 2a + 1 = 2a+1 = 2(98) + 1 = 197
A Solution for the absolute diferance of any 2 consecutive squares
(99+98)(99-98)=197
(100-1)^2-(100-2)2= 100^2+1-200-100^2-4+400
=197
let x = 99, then x^2 - (x-1)^2 = x^2 - (x^2-2x+1)=2x-1=2*99 - 1 = 197 =D
(a^2)-(b^2)=(a+b)(a-b) =(99^2)-(98^2)=(99+98)(99-98)=197
sorry this is wrong 5^2-3^2 not equal 2 but 16
I just added 99 and 98 together. Is it logical to u guys?
99^2 = 99 * 99 = 9801 ;98^2 = 98 * 98 = 9604 ;9801-9604 = 197
99^2 - 98^2 = (98+1)^2-98^2 = (98^2 + 2*98 +1) - 98^2 = 197
(100-1)^2-(100-2)^2=(100^2-200+1-100^2+400-4)=197
99^2 - 98^2
= (100-1)^2 - (100-2)^2 - Step 1
Using the formula (a-b)^2 = a^2-2ab+b^2, we can compute step 2 to be
9801 - 9604 = 197
(98+1)^2-(98^2)= (98^2)+98+98+1-(98^2)
99²-98²=197 (99x99)-(98x98) =197 9801-9604 = 197
SIMPLE SOLUTION ^^
Simple if it is square of both then the difference is the sum of them.Like 99²-98²=99+98 =197
99^2-98^2 =(98+1)^2-98^2 =98^2+1^2+2 98 1-98^2 =1+196 =197
99^2=98^2+98+99 so 99^2-98^2=98+99=197
If a=2 and b=1, then
x | = | a 2 | - | b 2 |
x | = | 2 2 | - | 1 2 |
x | = | 4 | - | 1 |
x | = | 3 |
y | = | a | + | b |
y | = | 2 | + | 1 |
y | = | 3 |
Then
x | = | y | ||||
a 2 | - | b 2 | = | a | + | b |
X | = | 9 9 2 | - | 9 8 2 |
Y | = | 99 | + | 98 |
X | = | Y | ||||
9 9 2 | - | 9 8 2 | = | 99 | + | 98 |
So
X | = | 99 | + | 98 |
X | = | 197 |
The difference between squares of two positive consecutive numbers will always be the sum of those two numbers. So 99^2-98^2=99+98=197
99^{2} - 98^{2} = (98 + 1)^{2} - 98^{2} = (98^{2} +2 98+1) - 98^{2} = 2 98 + 1 = 197
in this way too, we can solve it (100-1)^2 - (100-2)^2 by using (a-b)^2 formula we can solve
a^2-b^2 = (a+b)(a-b) 99^2 - 98^2 = (99+98)(99-98) =197(1) = 197
a^2-b^2=(a+b)(a-b) 99^2-98^2=(99+98)(99-98) =197*1 =197
Logic/geometric solution : Draw a square with a 98 side into a 99 side one : result of exclusion is a horizontal stripe 99×1 and a vertical stripe 98×1. So answer is 98+99=197
99^2 - 98^2 = 99^2 - (99 - 1)^2 = 99^2 - (99^2 - 2 99 + 1) = 2 99 -1 = 197
98+99=197 bcoz difference b/w 2 consecutive squares is the sum of those 2 consecutive numbers
99 ka square ly gy nd phr usy 98 k square sy (-) minous kr dy gy :)
(99+98)(99-98) (197)(1) 197
98^2=(99-1)^2
99^2-(99^2-2x99+1)
=2x99-1=197
a^-b^=(a+b)(a-b)
99^-98^ =(99+98)(99-98)
(100-1)^{ 2 }-(100-2)^{ 2 }=((100^{ 2 })-(2 100 1)+1)-((100^{ 2 })-(2 100 2)+(2^{ 2 }))=400-200-4+1=197
(1+98)(1+98)-98^2 =1+2×98+98^2-98^2 =1+196 =197
99^2-98^2 = (100-1)^2 - (100-2)^2 = (10,000-200+1) - (10,000-400+4) =10,000-200+1-10,000+400-4 =200-3 =197
Difference of two squares formula: 99^2 - 98^2= (99 + 98)(99 - 98)= (197)(1)= 197
99^2 - 98^= 9801 - 9604=197
99^2-98^2=(98+1)^2-98^2=98^2+2 98 1+1-98^2=196+1=197
99^2 -98^2 =(99+98) =197
You ccould've shown how you got: 99^2 -98^2 =(99+98).
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{ a }^{ 2 }-{ b }^{ 2 }=(a+b)(a-b)\\ { 99 }^{ 2 }-{ 98 }^{ 2 }=(99+98)(99-98)\\ \quad \quad \quad \quad =(197)(1)\\ \quad \quad \quad \quad =\boxed { 197 }